A supercritical airfoil is designed Group of answer choices A) to allow the normal shock wave to occur where the upper surface pressure gradient is favorable. B) with less curvature on the upper surface. C) to lower the critical Mach number. both A and B above.

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?